Application of a New Catalyst Deactivation Model for Residue Hydrotreating

This article reports a new catalyst deactivation model for residue hydrotreating technology(RHT)with three adjustable parameters,named as“active-region-migration model”.The active-region-migration model is proposed to describe the catalyst deactivation of RHT where the catalysts are deactivated due to metal loading.Along with the lumped reaction kinetics,the deactivation model can be applied to simulate the hydrogenation reaction performance in RHT.Industrial data from a commercial RHT unit show reasonably good agreements with the model calculations.Essentially,the active-region-migration model can separately simulate the catalytic-activity change of each hydrogenation reaction during the whole run of RHT,with a single curve.

Rank-based deactivation model for networks with age

We study the impact of age on network evolution which couples addition of new nodes and deactivation of old ones. During evolution, each node experiences two stages： active and inactive. The transition from the active state to the inactive one is based on the rank of the node. In this paper, we adopt age as a criterion of ranking, and propose two deactivation models that generalize previous research. In model A, the older active node possesses the higher rank, whereas in model B, the younger active node takes the higher rank. We make a comparative study between the two models through the node-degree distribution.

Capture of carbon dioxide by amine-impregnated as-synthesized MCM-41

The novel carbon dioxide （CO2） adsorbents with a high capture efficiency were prepared through impregnating the as-synthesized MCM-41 with three kinds of amines, namely diethylenetriamine （DETA）, triethylenetetramine （TETA） and 2-amino-2-methyl-1- propanol （AMP）. The resultant samples were characterized by small angle X-ray diff action and low temperature N2 adsorption. The synthesis way not only saves the energy or extractor to remove the template but also is environmentally friendly due to the absence of the potential pollutants such as toluene. CO2 capture was investigated in a dynamic packed column. The sample impregnated by TETA showed the highest adsorption capacity, approximately 2.22 mmol/g at 60℃ due to its highest amino-groups content among the three amines. The CO2 adsorption behavior was also investigated with the deactivation model, which showed an excellent prediction for the breakthrough curves.

Adsorption of carbon dioxide on amine-modified TiO_2 nanotubes

TiO2 nanotubes （TiNT） were prepared by a hydrothermal treatment and modified by three kinds of amines,namely ethylenediamine,polyetherimide and tetraethylenepentamine （TEPA）,to study their CO2 adsorption properties from gas streams.The resultant samples were characterized by X-ray diffraction,transmission electron microscopy,and infrared spectroscopy,as well as low temperature N 2 adsorption.CO2 capture was investigated in a dynamic packed column at 30℃.TEPA-modified TiO2 nanotubes showed the highest adsorption capacity of 167.64 mg/g because it had the highest amino-group content among the three amines.CO2 fixation on TiNT impregnated by TEPA was investigated at 30,50,and 70℃,and the adsorption capacity increased slightly with temperature.Following the adsorption step,the sorbents were regenerated by temperature programmed desorption,and the TiNT-TEPA sample,as CO2 sorbent,was found to be readily regenerated and energy-efficient.The cycle test also revealed that the TiNT-TEPA adsorbent is fairly stable,with only a 5% drop in the adsorption capacity after 10 adsorption/desorption cycles.In addition,the CO2 adsorption behavior was investigated with the deactivation model,and which showed an excellent prediction for the TiNT-TEPA breakthrough curves.